This invention relates to laser gyroscopes and more particularly to a laser gyroscope employing thin film technology in which the clockwise and counterclockwise beams do not coexist in the resonator.
Laser gyroscopes operate by propagating clockwise and counterclockwise beams of light into a resonator. If the resonator has an angular velocity in the plane of the resonator, the apparent path length for one of the beams will be longer than that of the counter propagating beam. Therefore, the resonance conditions for the two beams are no longer the same. In order to bring both beams back into resonance, biasing must be provided to compensate for the apparent change in path length both in the clockwise and counterclockwise directions.
When both the clockwise and counterclockwise beams exist simultaneously in the resonator, various detrimental interaction effects may result such as beats, backscatter and feedback into the laser. These interactions degrade the performance of such a laser gyroscope.
It is therefore an object of this invention to provide a passive ring resonator laser gyroscope which substantially eliminates interaction effects such as beats, backscatter and feedback into the laser.
Yet another object of this invention is a laser gyroscope utilizing thin film technology to produce a gyroscope which is extremely compact, reliable and easy to manufacture.